Need a inexpensive way to cool the pond water. Phoenix AZ current temp HOT!!

I live in Peoria AZ and from mid June till mid Sept its over 100
degrees every day even at 3am its 100. My poor fish have to endure
extreem pond temps, I dont know exactly what the pond temp is but I
would guess about 90 degrees. I just got done doubling the size of it.
I would guess it's about 700 gal give or take.
1250gph pump to my UV filter, Bio Filter, & water fall. Filtration and
airiation is pretty good but the fish hide during the day trying to
stay out of the Sun... Good luck out here. I have some pigmy palms to
the back of the pond and the pond has the block wall fence on two sides
of it and I have a Ficus tree in front of it but the tree is still
young and not big enough to provide any shade yet. On top of everything
my house faces east west so the back yard gets direct son for about 6
hours.
I have read about using a small dorm size fridge and converting it to
cool the water in the pond. I would like to hear from other AZ ponders
and know if you all are doing anything for cooling your pond temps.

Thanks,
Chris